Training vs Retrieval vs Tool Use
Definition
AI systems use three primary mechanisms to generate answers: training data (pre-learned knowledge), retrieval (fetching external sources), and tool use (calling APIs or functions).
Why It Exists
Different mechanisms serve different purposes. Training data provides broad knowledge but may be outdated. Retrieval provides current information. Tool use enables real-time actions and calculations.
What Changed
Modern AI systems increasingly combine all three mechanisms, moving beyond pure training-data responses to hybrid approaches that can access current information and perform actions.
What Breaks
Traditional SEO models that assume all answers come from indexed web pages break when answers come from training data or tool outputs that have no direct web presence.
What Replaces It
Visibility models must account for selection into training data, retrieval systems, and tool integrations—not just web page rankings.